The subject of the present invention is an exhaust gas recirculation device for an internal combustion engine. Many internal combustion engines and the majority of diesel engines are equipped with exhaust gas recirculation devices. Exhaust gas recirculation devices makes it possible to recycle a part of the exhaust gas from the engine into the air intake distributor thereof. The proportion of the gasses thus recycled is of order 5 to 50% as a general rule.
An exhaust gas recirculation device, usually called EGR, more specifically has the function of reducing the pollution generated by internal combustion engines so as to satisfy the standards imposed by regulatory authorities. Such pollution limiting regulations tend to become stricter over time.
The recirculation of a part of the exhaust gases from an engine slows the combustion of the gaseous mixtures supplying the cylinders and absorbs a part of the calories (heat), thereby reducing the combustion temperature.
Further, the presence of an EGR device leads to a limitation of the quantity of oxygen present in the cylinders.
These two effects combine leading to a reduction of the nitrogen oxides (NOx), which are the origin of atmospheric pollution by ozone.
Engine exhaust gas recirculation however has the disadvantage of increasing the production of polluting particles, particularly in the case of diesel engines. It is therefore necessary to find a compromise between the reduction of the nitrogen oxides NOx and the increase of the polluting particle emissions.
For this purpose, it currently is proposed to cool the gasses before they enter into the air intake distributor. In fact, the reduction of the temperature of these gases makes it possible to notably lower the particulate pollution for the same proportion of recycled gasses.
Subsequently, the exhaust gas recirculation devices currently offered on the market comprise a pipe for return of these gases to the intake distributor provided with a heat exchanger, as a general rule equipped with a cooling water circuit.
However, the presence of a heat exchanger has the disadvantage of notably increasing the cost of the EGR devices.
Therefore, there remains a need in the art for an exhaust gas recirculation device configured to provide cooling of recycled gases without requiring the use of a heat exchanger.